Thanks for the question.
Is your question how to change the trans fluid?
First unscrew the big nut that is on the bottom of the pan.
After that has drained, remove all the pan bolts. Remove the pan. There will still be some oil in the pan. Clean pan. Reinstall the big nut.
You need to put 4 qts of mercon 5 in the pan then install the pan on the trans and tighten all the bolts. You will need a nipple cap on the next 3 bottles of mercon 5 so you can push the trans fluid up into the pan. With the pan installed with the 4 qts. Start the engine and place it and drive and wait about 30 seconds then do the same in reverse. Now place it in park and leave it running. Now remove the center drain plug from the center of the big drain plug. Use your next 2 or 3 qts to squirt fluid up into the drain hole through the drain plug. Keep squirting fluid in it till it starts to come back out in a steady stream. When it is full only a small steady stream will come out, at that point cap off the hole and tighten the plug.